The value of naturally occurring estrogens and synthetic compositions demonstrating xe2x80x9cestrogenicxe2x80x9d activity has been in their medical and therapeutic uses. A traditional listing of the therapeutic applications for estrogens alone or in combination with other active agents includes: oral contraception; relief for the symptoms of menopause; prevention of threatened or habitual abortion; relief of dysmenorrhea; relief of dysfunctional uterine bleeding; an aid in ovarian development; treatment of acne; diminution of excessive growth of body hair in women (hirsutism); the prevention of cardiovascular disease; treatment of osteoporosis; treatment of prostatic carcinoma; and suppression of post-partum lactation [Goodman and Gilman, The Pharmacological Basis Of Therapeutics (Seventh Edition) Macmillan Publishing Company, 1985, pages 1421-1423]. Accordingly, there has been increasing interest in finding newly synthesized compositions and new uses for previously known compounds which are demonstrably estrogenic, this is, able to mimic the action of estrogen in estrogen responsive tissue.
From the viewpoint of pharmacologists interested in developing new drugs useful for the treatment of human diseases and specific pathological conditions, it is most important to procure compounds with some demonstrable estrogen-like function but which are devoid of proliferative side-effects. Exemplifying this latter view, osteoporosis, a disease in which bone becomes increasingly more fragile, is greatly ameliorated by the use of fully active estrogens; however, due to the recognized increased risk of uterine cancer in patients chronically treated with active estrogens, it is not clinically advisable to treat osteoporosis in intact women with fully active estrogens for prolonged periods. Accordingly estrogen agonists are the primary interest and focus.
Osteoporosis is a systemic skeletal disease, characterized by low bone mass and deterioration of bone tissue, with a consequent increase in bone fragility and susceptibility to fracture. In the U.S., the condition affects more that 25 million people and causes more than 1.3 million fractures each year, including 500,000 spine, 250,000 hip and 240,000 wrist fractures annually. These cost the nation over $10 billion. Hip fractures are the most serious, with 5-20% of patients dying within one year, and over 50% of survivors being incapacitated.
The elderly are at greatest risk of osteoporosis, and the problem is therefore predicted to increase significantly with the aging of the population. Worldwide fracture incidence is forecast to increase three-fold over the next 60 years, and one study estimates that there will be 4.5 million hip fractures worldwide in 2050. Women are at greater risk of osteoporosis than men. Women experience a sharp acceleration of bone loss during the five years following menopause. Other factors that increase the risk include smoking, alcohol abuse, a sedentary lifestyle and low calcium intake.
Estrogen is the agent of choice in preventing osteoporosis or post menopausal bone loss in women; it is the only treatment which unequivocally reduces fractures. However, estrogen stimulates the uterus and is associated with an increased risk of endometrial cancer. Although the risk of endometrial cancer is thought to be reduced by a concurrent use of a progestogen, there is still concern about possible increased risk of breast cancer with the use of estrogen.
There is a need for improved estrogen agonists which exert selective effects on different tissues in the body. Tamoxifen, 1-(4-xcex2-dimethylaminoethoxyphenyl)-1,2-diphenyl-but-1-ene, is an antiestrogen which has a palliative effect on breast cancer, but is reported to have estrogenic activity in the uterus.
Recently it has been reported (Osteoporosis Conference Scrip No. 1812/13 Apr. 16/20, 1993, p29) that raloxifene, 6-hydroxy-2-(4-hydroxyphenyl)-3-[4-(2-piperidinoethoxy)benzoyl]benzo[b]thiophene, mimics the favorable action of estrogen on bone and lipids but, unlike estrogen, has minimal uterine stimulatory effect. (Breast Cancer Res. Treat. 10(1). 1987 p 31-36 Jordan, V.C. et al.)
Raloxifene as well as ethers and esters thereof and related compounds are described as antiestrogen and antiandrogenic materials which are effective in the treatment of certain mammary and prostate cancers. See U.S. Pat. No. 4,418,068 and Charles D. Jones, et al., J. Med. Chem. 1984, 27, 1057-1066.
Jones, et al in U.S. Pat. No. 4,133,814 describe derivatives of 2-phenyl-3-aroylbenzothiophene and 2-phenyl-3-aroylbenzothiophene-1-oxides which are useful as antifertility agents as well as suppressing the growth of mammary tumors.
Related 2-phenyl-3-aroylbenzothiophenes have also been claimed to modulate the clearance of antibody coated cells from the circulation of mammals, thus providing a method of treating autoimmune disease, U.S. Patent No. 5,075,321.
This invention provides compounds of the formula 
wherein
A, B and Z are independently
(a) xe2x80x94CHxe2x95x90,
(b) xe2x80x94CR4xe2x95x90,
(c) xe2x95x90Nxe2x80x94;
X is
(a) xe2x80x94Sxe2x80x94,
(b) xe2x80x94Oxe2x80x94,
(c) xe2x80x94NHxe2x80x94,
(d) xe2x80x94NR2xe2x80x94,
(e) xe2x80x94CH2CH2xe2x80x94,
(f) xe2x80x94CH2CH2CH2xe2x80x94,
(g) xe2x80x94CH2Oxe2x80x94,
(h) xe2x80x94OCH2xe2x80x94,
(i) xe2x80x94CH2Sxe2x80x94,
(j) 
(k) xe2x80x94SCH2xe2x80x94,
(l) xe2x80x94Nxe2x95x90CR2xe2x80x94,
(m) xe2x80x94R2Cxe2x95x90Nxe2x80x94;
Y is
(a) phenyl, optionally substituted with 1-3 substituents independently selected from the group consisting of halo, hydroxy, C1-C4 alkyl, C1-C4 alkoxy, 
xe2x80x83and R1SO2NHxe2x80x94;
(b) C1-C8 alkyl, said alkyl groups being optionally substituted with 1-3 substituents independently selected from the group consisting of 
xe2x80x83and R1SO2NHxe2x80x94;
(c) C3-C8 cycloalkyl, optionally substituted with 1-2 substituents independently selected from the group consisting of xe2x80x94OH,xe2x80x94R1, 
xe2x80x83and R1SO2NHxe2x80x94;
(d) C3-C8 cycloalkenyl, optionally substituted with 1-2 substituents independently selected from the group consisting of xe2x80x94OH, 
xe2x80x83and R1SO2NHxe2x80x94;
(e) a five membered heterocycle containing up to two heteroatoms selected from the group consisting of xe2x80x94Oxe2x80x94, xe2x80x94NR2xe2x80x94 and xe2x80x94S(O)nxe2x80x94, optionally substituted with 1-3 substituents independently selected from the group consisting of hydrogen, hydroxyl, halo, C1-C4 alkyl, trihalomethyl, C1-C4 alkoxy, trihalomethoxy, C1-C4 acyloxy, C1-C4 alkylthio, C1-C4 alkylsulfinyl, C1-C4 alkylsulfonyl, hydroxy (C1-C4)alkyl, aryl (C1-C4)alkyl,xe2x80x94CO2H, xe2x80x94CN, xe2x80x94CONHOR1, xe2x80x94SO2NHR1, xe2x80x94NH2, C1-C4 alkylamino, C1-C4 dialkylamino, xe2x80x94NHSO2R1,xe2x80x94NHCOR1, xe2x80x94NO2, and -aryl;
a six membered heterocycle containing up to two heteroatoms selected from the group consisting of xe2x80x94Oxe2x80x94, xe2x80x94NR2xe2x80x94 and xe2x80x94S(O)nxe2x80x94 optionally substituted with 1-3 substituents independently selected from the group consisting of hydrogen, hydroxyl, halo, C1-C4 alkyl, trihalomethyl, C1-C4 alkoxy, trihalomethoxy, C1-C4 acyloxy, C1-C4 alkylthio, C1-C4 alkylsulfinyl, C1-C4 alkylsulfonyl, hydroxy (C1-C4)alkyl, aryl (C1-C4)alkyl,xe2x80x94CO2H, xe2x80x94CN, xe2x80x94CONHOR1, xe2x80x94SO2NHR1, xe2x80x94NH2, C1-C4 alkylamino, C1-C4 dialkylamino, xe2x80x94NHSO2R1,xe2x80x94NHCOR1, xe2x80x94NO2, and -aryl;
(g) a bicyclic ring system consisting of a five or six membered heterocyclic ring fused to a phenyl ring, said heterocyclic ring containing up to two heteroatoms selected from the group consisting of xe2x80x94Oxe2x80x94, xe2x80x94NR2xe2x80x94 and xe2x80x94S(O)nxe2x80x94, optionally substituted with 1-3 substituents independently selected from the group consisting of hydrogen, halo, C1-C4 alkyl, trihalomethyl, C1-C4 alkoxy, trihalomethoxy, C1-C4 acyloxy, C1-C4 alkylthio, C1-C4 alkylsulfinyl, C1-C4 alkylsulfonyl, hydroxy (C1-C4)alkyl, aryl (C1-C4)alkyl,xe2x80x94CO2H, xe2x80x94CN, xe2x80x94CONHOR1, xe2x80x94SO2NHR1, xe2x80x94NH2, C1-C4 alkylamino, C1-C4 dialkylamino, xe2x80x94NHSO2R1, xe2x80x94NHCOR1, xe2x80x94NO2, xe2x80x94OH, and -aryl;
D is
(a) xe2x80x94COxe2x80x94,
(b) xe2x80x94CR2R3xe2x80x94,
(c) xe2x80x94CONHxe2x80x94,
(d) xe2x80x94NHCOxe2x80x94,
(e) xe2x80x94CR2 (OH)xe2x80x94,
(f) xe2x80x94CONR2xe2x80x94,
(g) xe2x80x94NR2COxe2x80x94, 
E is
(a) a single bond;
(b) phenyl, or phenyl substituted with up to three substituents independently selected from the group consisting of hydrogen, halo, C1-C4 alkyl, trihalomethyl, C1-C4 alkoxy, trihalomethoxy, C1-C4 acyloxy, C1-C4 alkylthio, C1-C4 alkylsulfinyl, C1-C4 alkylsulfonyl, hydroxy (C1-C4)alkyl, aryl (C1-C4)alkyl,xe2x80x94CO2H, xe2x80x94CN,xe2x80x94CONHOR, xe2x80x94SO2NHR, xe2x80x94NH2, C1-C4 alkylamino, C1-C4 dialkylamino, xe2x80x94NHSO2R, xe2x80x94NHCOR1,xe2x80x94NO2, and -aryl; or
(c) a 5 or 6 membered heterocycle, optionally fused to a phenyl ring containing up to two heteroatoms selected from the group consisting of xe2x80x94Oxe2x80x94, xe2x80x94NR2xe2x80x94 and xe2x80x94S(O)nxe2x80x94 optionally substituted with 1-3 substituents independently selected from the group consisting of hydrogen, halo, C1-C4 alkyl, trihalomethyl, C1-C4 alkoxy, trihalomethoxy, C1-C4 acyloxy, C1-C4 alkylthio, C1-C4 alkylsulfinyl, C1-C4 alkylsulfonyl, hydroxy (C1-C4) alkyl, aryl (C1-C4) alkyl, xe2x80x94CO2H, xe2x80x94CN,xe2x80x94CONHOR, xe2x80x94SO2NHR, xe2x80x94NH2, C1-C4 alkylamino, C1-C4 dialkylamino, xe2x80x94NHSO2R,xe2x80x94NHCOR1, xe2x80x94NO2, and -aryl;
Z1 is
(a) xe2x80x94(CH2)p W(CH2)qxe2x80x94,
(b) xe2x80x94O(CH2)p CR5 R6xe2x80x94,
(c) xe2x80x94O(CH2)pW(CH2)q;
G is
(a) xe2x80x94NR7 R8,
(b) 
xe2x80x83wherein n is 0, 1 or 2; m is 1, 2 or 3; Z2 is xe2x80x94NHxe2x80x94,xe2x80x94Oxe2x80x94,xe2x80x94Sxe2x80x94, or xe2x80x94CH2xe2x80x94; optionally fused on adjacent carbon atoms with one or two phenyl rings and, optionally independently substituted on carbon with one to three substituents and, optionally, independently on nitrogen with a chemically suitable substituent selected from 
(e) a 5 or 6 membered heterocycle containing up to two heteroatoms selected from the group consisting of xe2x80x94Oxe2x80x94, xe2x80x94NR2xe2x80x94and xe2x80x94S(O)nxe2x80x94optionally substituted with 1-3 substituents independently selected from the group consisting of hydrogen, halo, C1-C4 alkyl, trihalomethyl, C1-C4 alkoxy, trihalomethoxy, C1-C4 acyloxy, C1-C4 alkylthio, C1-C4 alkylsulfinyl, C1-C4 alkylsulfonyl, hydroxy (C1-C4)alkyl, aryl (C1-C4)alkyl,xe2x80x94CO2H, xe2x80x94CN, xe2x80x94CONHOR, xe2x80x94SO2NHR, xe2x80x94NH2, C1-C4 alkylamino, C1-C4 dialkylamino, xe2x80x94NHSO2R,xe2x80x94NHCOR1, xe2x80x94NO2,and -aryl; said heterocycle being joined to group Z1 by a carbon to carbon bond or carbon-nitrogen bond;
(f) a bicyclic amine containing a five to twelve carbon atoms, either bridged or fused and optionally substituted with 1-3 substituents independently selected from the group consisting of hydrogen, halo, C1-C4 alkyl, trihalomethyl, C1-C4 alkoxy, trihalomethoxy, C1-C4 acyloxy, C1-C4 alkylthio, C1-C4 alkylsulfinyl, C1-C4 alkylsulfonyl, hydroxy (C1-C4)alkyl, aryl (C1-C4)alkyl , xe2x80x94CO2H , xe2x80x94CN,xe2x80x94CONHOR, xe2x80x94SO2NHR, xe2x80x94NH2, C1-C4 alkylamino, C1-C4 dialkylamino, xe2x80x94NHSO2R,xe2x80x94NHCOR1, xe2x80x94NO2, and -aryl;
Z1 and G in combination may be 
xe2x80x83Ar is phenyl or naphthyl optionally substituted with up to three substituents independently selected from R4;
W is
(a) xe2x80x94CH2xe2x80x94,
(b) xe2x80x94CHxe2x95x90CHxe2x80x94,
(c) xe2x80x94Oxe2x80x94,
(d) xe2x80x94NR2xe2x80x94,
(e) xe2x80x94S(O)nxe2x80x94, 
(g) xe2x80x94CR2(OH)xe2x80x94,
(h) xe2x80x94CONR2xe2x80x94,
(i) xe2x80x94NR2COxe2x80x94,
(j) 
(k) xe2x80x94Cxe2x89xa1Cxe2x80x94;
R is
(a) halogen,
(b) xe2x80x94NR3R2,
(c) xe2x80x94NHCOR2,
(d) xe2x80x94NHSO2R2,
(e) xe2x80x94CR2R3OH,
(f) xe2x80x94CONR2R3,
(g) xe2x80x94SO2NR2R3,
(h) hydroxyl,
(i) R1Oxe2x80x94, 
R1is C1-C6 alkyl or phenyl optionally substituted with up to three substituents independently selected from C1-C6 alkyl, halogen, alkoxy, hydroxy and carboxy;
R2 and R3 are independently
(a) hydrogen,
(b) C1-C4 alkyl;
R4 is
(a) hydrogen,
(b) halogen,
(c) C1-C4 alkyl,
(d) C1-C4 alkoxy,
(e) C1-C4 acyloxy,
(f) C1-C4 alkylthio,
(g) C1-C4 alkylsulfinyl,
(h) C1-C4 alkylsulfonyl,
(i) hydroxy (C1-C4)alkyl,
(j) aryl (C1-C4)alkyl,
(k) xe2x80x94CO2H,
(l) xe2x80x94CN,
(m) xe2x80x94CONHOR,
(n) xe2x80x94SO2NHR,
(o) xe2x80x94NH2,
(p) C1-C4 alkylamino,
(q) C1-C4 dialkylamino,
(r) xe2x80x94NHSO2R,
(s) xe2x80x94NO2,
(t) -aryl;
R5 and R6 are independently C1-C8 alkyl or together form a C3-C10 carbocyclic ring;
R7 and R8 are independently
(a) phenyl,
(b) a C3-C10 carbocyclic ring, saturated or unsaturated,
(c) a C3-C10 heterocyclic ring containing up to two heteroatoms, selected from xe2x80x94Oxe2x80x94, xe2x80x94Nxe2x80x94 and xe2x80x94Sxe2x80x94
(d) H,
(e) C1-C6 alkyl,
(f) or form a 3 to 8 membered nitrogen containing ring with R5 or R6;
R7 and R8 in either linear or ring form may optionally be substituted with up to three substituents independently selected from C1-C6 alkyl, halogen, alkoxy, hydroxy and carboxy;
a ring formed by R7 and R8 may be optionally fused to a phenyl ring;
m is 1, 2 or 3;
n is 0, 1 or 2;
p is 0, 1, 2 or 3;
q is 0, 1, 2, or 3;
and geometric and optical isomers, pharmaceutically acceptable esters, ethers and salts thereof;
with the proviso that when A, B and Z are each xe2x80x94CHxe2x95x90, Y is 4-hydroxy phenyl, X is sulfur, D is xe2x80x94COxe2x80x94, E is 1,4-disubstituted phenyl, R is xe2x80x94OH, and Z1 is xe2x80x94OCH2 CH2xe2x80x94 then G must be a group other than 
or xe2x80x94Nxe2x80x94(C1-C4 alkyl)2; and with the further proviso that if R is 
G must be a group other than 
and with the further proviso that when A, B and Z are each xe2x80x94CHxe2x95x90, X is S,Y is cycloalkyl or cycloalkenyl; 
E is 1,4 disubstituted phenyl; and Z1 is methylene, O(CH2)mxe2x80x94, ethylene or propylene; G must be other than 
and with the further proviso that when D is xe2x80x94CR2R3xe2x80x94 and W is xe2x80x94COxe2x80x94 or xe2x80x94S(O)nxe2x80x94; G must be other than:
a) xe2x80x94NR11R12 where R11 and R12 are separately hydrogen, alkyl, alkenyl, cycloalkyl, haloalkyl, aryl or arylalkyl; 
where n is 0, 1 or 2; m is 1, 2 or 3; and Z2 is xe2x80x94NHxe2x80x94, Oxe2x80x94, xe2x80x94Sxe2x80x94 or xe2x80x94CH2xe2x80x94;
and with the further proviso that when A, B and Z are each xe2x80x94CHxe2x95x90, Y is 4-hydroxyphenyl, X is xe2x80x94CH2xe2x80x94CH2xe2x80x94 or xe2x80x94CHxe2x95x90CHxe2x80x94; D is CO, E is 1,4-disubstituted phenyl, and Z1 is xe2x80x94OCH2CH2xe2x80x94; then G must be a group other than 
This invention provides preferred groups of compounds of formula 1 wherein
1. R is xe2x80x94OH ;
2. A, B and Z are independently selected from xe2x80x94CHxe2x95x90 and xe2x80x94CFxe2x95x90;
3. X is xe2x80x94Sxe2x80x94;
4. D is xe2x80x94COxe2x80x94 or CH2xe2x80x94;
5. E is 1,4-linked phenyl, pyridyl, pyrimidine, 
6. Z1 is xe2x80x94OCH2CH2xe2x80x94, xe2x80x94CH2CH2xe2x80x94, xe2x80x94CH2xe2x80x94, 
7. G is 
8. R is xe2x80x94OH ; A, B and Z are xe2x80x94CHxe2x80x94; X is S; Y is 
A further preferred group of compounds are those of formula 1 wherein:
A, B and Z are xe2x80x94CHxe2x95x90;
X is xe2x80x94Sxe2x80x94;
Y is phenyl, 4-hydroxyphenyl, 4-chlorophenyl, 4-fluorophenyl, 
R is xe2x80x94OHxe2x80x94;
D is xe2x80x94COxe2x80x94 or xe2x80x94CH2xe2x80x94;
E is phenyl or pyridyl; and
Z1 is xe2x80x94OCH2CH2xe2x80x94, xe2x80x94Cxe2x89xa1Cxe2x80x94CH2xe2x80x94, xe2x80x94OCH2xe2x80x94, or xe2x80x94NHCH2CH2xe2x80x94.
Further preferred with the above group are those compounds wherein: 
m is 1, 2 or 3 and Z2 is xe2x80x94NHxe2x80x94, xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94 or xe2x80x94CH2xe2x80x94.
Or those compounds wherein G is: 
Or those compounds wherein G is: 
In another aspect this invention provides intermediate compounds of the formula 
wherein:
J, J1 and J2 are independently xe2x80x94H, xe2x80x94CH3, xe2x80x94SO2CH3 or xe2x80x94SO2CF3; and 
with the proviso that only two of J, J1 and J2 may be xe2x80x94H.
In yet another aspect this invention provides a method of treating bone loss associated with estrogen deficiency in a mammal which comprises administering to a mammal in need of such treatment an amount of a compound of claim 1 which is effective in treating said bone loss.
In yet another aspect this invention provides pharmaceutical composition comprising an amount of compound of claim 1 which is effective in treating estrogen deficiency bone loss in a mammal and a pharmaceutically inert carrier.
In yet another aspect this invention provides a method for the treatment or prevention of cardiovascular disease which comprises administering to a mammal in need of such treatment an amount of a compound of claim 1 which is effective in treating or preventing said cardiovascular disease.
In yet another aspect this invention provides a method of treating a mammal having a mammary tumor which comprises administering to said mammal a mammary tumor-inhibiting effective amount of a compound of claim 1.
In yet another aspect this invention provides a method for the treatment or prevention of diseases or syndromes which are caused by an estrogen deficient state in a mammal which comprises administering to a mammal in need of such treatment or prevention an amount of a compound of claim 1 which is effective in treating said disease or syndrome.
In this document, all measurements are expressed in weight units, unless otherwise stated, except that ratios of solvents are expressed in volume units.
The general chemical terms used in the formulae above have their usual meanings. For example, the terms C1-C14 alkyl, and C1-C4 alkoxy include groups such as methyl, ethyl, isopropyl, butyl, s-butyl, tetradecyl, undecyl, neopentyl, 2,2-dimethylhexyl, 3-ethylnonyl, 3-butylheptyl, dodecyl, methoxy, propoxy and i-butoxy.
The terms C1-C3 chloroalkyl and C1-C3 fluoroalkyl include methyl, ethyl, propyl and isopropyl substituted to any desired degree with chlorine or fluorine atoms, from one atom to full substitution. The term C5-C7 cycloalkyl includes cyclopentyl, cyclohexyl and cycloheptyl.
Halo means chloro, bromo, iodo and fluoro. Aryl (Ar) includes phenyl and naphthyl optionally substituted with one to three substituents independently selected from R4 as defined above. DTT means dithiothreitol. DMSO means dimethyl sulfoxide. EDTA means ethylene diamine tetra acetic acid.
Estrogen agonists are herein defined as chemical compounds capable of binding to the estrogen receptor sites in mammalian tissue, and mimic the actions of estrogen in one or more tissues.
One of ordinary skill will recognize that certain substituents listed in this invention will be chemically incompatible with one another or with the heteroatoms in the compounds, and will avoid these incompatibilties in selecting compounds of this invention.
The chemist of ordinary skill will recognize that certain compounds of this invention will contain atoms which may be in a particular optical or geometric configuration. All such isomers are included in this invention.
Likewise, the chemist will recognize that various pharmaceutically acceptable esters, ethers and salts may be prepared from certain compounds of this invention. All of such esters, ethers and salts are included in this invention.
The compounds of this invention are valuable estrogen agonists and pharmaceutical agents or intermediates thereto. Those which are estrogen agonists are useful for oral contraception; relief for the symptoms of menopause; prevention of threatened or habitual abortion; relief of dysmenorrhea; relief of dysfunctional uterine bleeding; an aid in ovarian development; treatment of acne; diminution of excessive growth of body hair in women (hirsutism); the prevention and treatment of cardiovascular disease; prevention and treatment of atherosclerosis; prevention and treatment of osteoporosis; treatment of prostatic carcinoma; and suppression of post-partum lactation. These agents also have a beneficial effect on plasma lipid levels.
While the compounds of this invention are estrogen agonists in bone, they are also antiestrogens in breast tissue and as such would be useful in the treatment and prevention of breast cancer.
Bone Mineral Density
Bone mineral density, a measure of bone mineral content, accounts for greater than 80% of a bone""s strength. Loss of bone mineral density with age and/or disease reduces a bone""s strength and renders it more prone to fracture. Bone mineral content is accurately measured in people and animals by dual x-ray absorptiometry (DEXA) such that changes as little as 1% can be quantified. We have utilized DEXA to evaluate changes in bone mineral density due to estrogen deficiency following ovariectomy (surgical removal of ovaries) and treatment with vehicle, estradiol (E2), keoxifen (raloxifen), or other estrogen agonists. The purpose of these studies was to evaluate the ability of the compounds of this invention to prevent estrogen deficiency bone loss as measured by DEXA.
Female (S-D) rats 4-6 months of age underwent bilateral ovariectomy or sham surgery and allowed to recover from anesthesia. Rats were s.c. injected with either 10 xcexcg estradiol or 100 xcexcg of compound daily for 28 days. All compounds were weighed and dissolved in 10% ethanol in sterile saline. After 28 days the rats were killed and femora removed and defleshed. The femoral were positioned on a Hologic QDR1000W (Hologic, Inc. Waltham, Mass.) and bone mineral density was determined in the distal portion of the femur at a site from 1 cm to 2 cm from the distal end of the femur using the high resolution software supplied by Hologic. Bone mineral density is determined by dividing the bone mineral content by the bone area of the distal femur. Each group contained at least 6 animals. Mean bone mineral density was obtained for each animal and statistical differences (p less than 0.05) from the vehicle-treated ovariectomy and sham-operated group were determined by t test.
In Vitro Estrogen Receptor Binding Assay
An in vitro estrogen receptor binding assay, which measures the ability of the compounds of the present invention to displace [3H]-estradiol from human estrogen receptor obtained by recombinant methods in yeast, was used to determine the estrogen receptor binding affinity of the compounds of this invention. The materials used in this assay were: (1) Assay buffer, TD-0.3 (containing 10 nM Tris, pH 7.6, 0.3 M potassium chloride and 5 mM DTT, pH 7.6); (2) The radioligand used was [3H]-estradiol obtained from New England Nuclear; (3) the cold ligand used was estradiol obtained from Sigma (4) recombinant human estrogen receptor, hER.
A solution of the compound being tested was made up in TD-0.3 with 4% DMSO and 16% ethanol. The tritiated estradiol was dissolved in TD-0.3 such that the final concentration in the assay was 5nM. The hER was also diluted with TD-0.3 such that 4-10 xcexcg of total protein was in each assay well. Using microtitre plates, each incubate received 50 ul of cold estradiol (nonspecific binding) or the compound solution, 20 uL of the tritiated estradiol and 30 ul of hER solutions. Each plate contained in triplicate total binding and varying concentrations of the compound. The plates were incubated overnight at 4xc2x0 C. The binding reaction was then terminated by the addition and mixing of 100 mL of 3% hydroxylapatite in 10 mM tris, pH 7.6 and incubation for 15 minutes at 4xc2x0 C. The mixtures was centrifuged and the pellet washed four times with 1% Triton-X100 in 10 mM Tris, pH 7.6. The hydroxylapatite pellets were suspended in Ecoscint A and radioactivity was assessed using beta scintigraphy. The mean of all triplicate data points (counts per minute, cpm""s) as determined. Specific binding was calculated by subtracting nonspecific cpm""s (defined as counts that remain following separation of reaction mixture containing recombinant receptor, radioligand, and excess unlabeled ligand) from total bound cpm""s (defined as counts that remain following the separation of reaction mixture containing only recombinant receptor, radioligand). Compound potency was determined by means of IC50 determinations (the concentration of a compound needed to inhibition 50% of the of the total specific tritiated estradiol bound). Specific binding in the presence of varying concentrations of compound was determined and calculated as percent specific binding of total specific radioligand bound. Data were plotted as percent inhibition by compound (linear scale) versus compound concentration (log scale). Compounds of the present invention were found to have IC50 values at or less than 20 pM.
Effect on Total Cholesterol Levels
The effect of the compounds of the present invention on plasma levels of total cholesterol was measured in the following way. Blood samples were collected via cardiac puncture from anesthetized female (S-D) rats 4-6 months of age that were bilaterally ovariectomized and treated with the compound (100 xcexcg/day sc for 28 days or with vehicle for the same time), or sham operated. The blood was placed in a tube containing 30 xcexcL of 5% EDTA (10 xcexcL EDTA/1 mL of blood). After centrifugation at 2500 rpm for 10 minutes at 20xc2x0 C. the plasma was removed and stored at xe2x88x9220xc2x0 C. unit assay. The total cholesterol was assayed using a standard enzymatic determination kit from Sigma Diagnostics (Procedure No. 352). Preferred compounds of the invention include:
[6-Hydroxy-2-(4-hydroxy-phenyl)-benzo[b]thiophen-3-yl]-{4-[2-(4-methyl-piperazin-1-yl)-ethoxy]-phenyl}-methanone;
1-(2-{4-[6-Hydroxy-2-(4-hydroxy-phenyl)-benzo[b]thiophene-3-carbonyl]-phenoxy}-ethyl)-piperidin-4-one;
{4-[2-(Bicyclo[2.2.1]hept-2-ylamino)-ethoxy]-phenyl}-[6-hydroxy-2-(4-hydroxy-phenyl)-benzo[b]thiophen-3-yl]-methanone;
[6-Hydroxy-2-(4-hydroxy-phenyl)-benzo[b]thiophen-3-yl]-{4-[2-(6-methyl-2-aza-bicyclo[2.2.1]hept-2-yl)-ethoxy]-phenyl}-methanone;
[4-(2-Cyclopropylamino-ethoxy)-phenyl]-[6-hydroxy-2-(4-hydroxy-phenyl) -benzo[b]thiophen-3-yl]-methanone;
{4-[2-(2-Aza-bicyclo[2.2.1]hept-2-yl)-ethoxy]-phenyl}-[6-hydroxy-2-(4hydroxy-phenyl) -benzo[b]thiophen-3-yl]-methanone;
[6-Hydroxy-2-(4-hydroxy-phenyl)-benzo[b]thiophen-3-yl]-[4-(1-methyl-2-piperidin-1-yl-ethoxy)-phenyl]-methanone;
[6-Hydroxy-2-(4-hydroxy-phenyl)-benzo[b]thiophen-3-yl]-[4-(1-methyl-piperidin-2-yl-methoxy)-phenyl]-methanone;
[6-Hydroxy-2-(4-hydroxy-phenyl)-benzo[b]thiophen-3-yl]-[6-(2-piperidin-1-yl-ethoxy)-pyridin-3-yl]-methanone;
[7-Fluoro-6-hydroxy-2-(4-hydroxy-phenyl)-benzo[b]thiophen-3-yl]-[4-(2-piperidin-1-yl-ethoxy)-phenyl]-methanone;
[2-(4-Fluoro-phenyl)-6-hydroxy-benzo[b]thiophen-3-yl]-[4-(2-piperidin-1-yl-ethoxy)-phenyl]-methanone;
{4-[2-(3,4-Dihydro-1H-isoquinolin-2-yl)-ethoxy]-phenyl}-[6-hydroxy-2-(4-hydroxy-phenyl)-benzo[b]thiophen-3-yl]-methanone;
(2-Benzothiazol-6-yl-6-hydroxy-benzo[b]thiophen-3-yl)-[4-(2-piperidin-1-yl-ethoxy)-phenyl]-methanone;
[2-(4-Chloro-phenyl)-6-hydroxy-benzo[b]thiophen-3-yl]-[4-(2-piperidin-1-yl-ethoxy)-phenyl]-methanone;
[6-Hydroxy-2-(tetrahydro-pyran-4-yl)-benzo[b]thiophen-3-yl]-[4-(2-piperidin-1-yl-ethoxy)-phenyl]-methanone;
[6-Hydroxy-2-(4-hydroxy-phenyl)-benzo[b]thiophen-3-yl]-[6-(2-piperidin-1-yl-ethylamino)-pyridin-3-yl]-methanone;
(6-Hydroxy-2-phenyl-benzo[b]thiophen-3-yl)-[4-(2-piperidin-1-yl-ethoxy)-phenyl]-methanone;
[6-Hydroxy-2-(4-hydroxy-phenyl)-benzo[b]thiophen-3-yl]-[4-(3-piperidin-1-yl-prop-1-ynyl)-phenyl]-methanone;
2-(4-Hydroxy-phenyl)-3-[4-(2-piperidin-1-yl-ethoxy)-benzyl]-benzo[b]thiophenol-6-ol;
[4-(2-Cyclobutylamino-ethoxy)-phenyl]-[6-hydroxy-2-(4-hydroxy-phenyl) -benzo[b]thiophen-3-yl]-methanone;
[4-(1-Ethyl-piperidin-2-ylmethoxy)-phenyl]-[6-hydroxy-2-(4-hydroxy-phenyl) -benzo[b]thiophen-3-yl]-methanone;
Especially preferred compounds of the invention include:
{4-[2-(2-Aza-bicyclo[2.2.1]hept-2-yl)-ethoxy]-phenyl}-[6-hydroxy-2-(4-hydroxy-phenyl)-benzo[b]thiophen-3-yl]-methanone;
[6-Hydroxy-2-(4-hydroxy-phenyl)-benzo[b]thiophen-3-yl]-[6-(2-piperidin-1-yl-ethoxy)-pyridin-3-yl]-methanone;
[6-Hydroxy-2-(4-hydroxy-phenyl)-benzo[b]thiophen-3-yl]-[4-(1-methyl-piperidin-2-yl-methoxy)-phenyl]-methanone;
[2-(4-Fluoro-phenyl)-6-hydroxy-benzo[b]thiophen-3-yl]-[4-(2-piperidin-1-yl-ethoxy)-phenyl]-methanone;
[6-Hydroxy-2-(4-hydroxy-phenyl)-benzo[b]thiophen-3-yl]-[4-(3-piperidin-1-yl-prop-1-ynyl)-phenyl]-methanone;
2-(4-Hydroxy-phenyl)-3-[4-(2-piperidin-1-yl-ethoxy)-benzyl]-benzo[b]thiophen-6-ol;
[4-(2-Cyclobutylamino-ethoxy)-phenyl]-[6-hydroxy-2-(4-hydroxy-phenyl) -benzo[b]thiophen-3-yl]-methanone;
[4-(1-Ethyl-piperidin-2-ylmethoxy)-phenyl]-[6-hydroxy-2-(4-hydroxy-phenyl) -benzo[b]thiophen-3-yl]-methanone,
[6-Hydroxy-2-(4-hydroxy-phenyl)-benzo[b]thiophen-3-yl]-{4-[2-(6-methyl-2-aza-bicyclo[2.2.1]hept-2-yl)-ethoxy]-phenyl}-methanone;
Intermediate compounds include the following:
[4-(3-Hydroxy-prop-1-ynyl)-phenyl]-[6-methoxy-2-(4-methoxy-phenyl) -benzo[b]thiophen-3-yl]-methanone;
Methanesulfonic acid 3-{4-[6-methoxy-2-(4-methoxy-phenyl) -benzo[b]thiophene-3-carbonyl]-phenyl}-prop-2-ynyl ester;
(4-lodo-phenyl)-[6-methoxy-2-(4-methoxy-phenyl)-benzo[b]thiophen-3-yl]-methanone;
[6-Hydroxy-2-(4-hydroxy-phenyl)-benzo[b]thiophen-3-yl]-(4-(piperidine-2-ylmethoxy)-phenyl)-methanone;
[6-Methoxy-2-(4-methoxy-phenyl)-benzo[b]thiophen-3-yl]-(4-hydroxy-phenyl)-methanone;
3-Bromo-6-methoxy-2-(4-methoxy-phenyl)-benzo[b]thiophene.
Trifluoro-methanesulfonic acid 2-(4-methanesulfonyloxy-phenyl)-3-[4-(2-piperidin-1-yl-ethoxy)-benzoyl]-benzo[b]thiophen-6-yl ester.
Pharmaceutical chemists will easily recognize that physiologically active compounds which have accessible hydroxy groups are frequently administered in the form of pharmaceutically acceptable esters or ethers. The literature concerning such compounds, such as estradiol, provides a great number of instances of such esters and ethers. The compounds of this invention are no exception in this respect, and can be effectively administered as an ether or ester, formed on the hydroxy groups, just as one skilled in pharmaceutical chemistry would expect. While the mechanism has not yet been investigated, it is believed that ethers and esters are metabolically cleaved in the body, and that the actual drug, which such form is administered, is the hydroxy compound itself. It is possible, as has long been known in pharmaceutical chemistry, to adjust the rate or duration of action of the compound by appropriate choices of ester or ether groups. For example, the cycloalkyl ethers are known to increase the duration of action of many hydroxy-group-bearing physiologically active compounds.
Certain ether and ester groups are preferred as constituents of the compounds of this invention. The compounds of formula I may contain ester or ether groups at various portions as defined herein above, where these groups are represented as xe2x80x94COOR9, and xe2x80x94OR10;
R9 is C1-C14 alkyl, C1-C3 chloroalkyl, C1-C3 fluoroalkyl, C5-C7 cycloalkyl, C1-C4 alkoxy, phenyl, or phenyl mono- or disubstituted with C1-C4 alkyl, C1-C4 alkoxy, hydroxy, nitro, chloro, fluoro or tri(clhoro or fluoro)methyl;
R10 is C1-C4 alkyl, C5-C7 cycloalkyl or benzyl; and the pharmaceutically acceptable acid addition salts thereof.
The pharmaceutically acceptable acid addition salts of the compounds of this invention may be formed of the compound itself, or of any of its esters or ethers, and include the pharmaceutically acceptable salts which are often used in pharmaceutical chemistry. For example, salts may be formed with inorganic or organic acids such as hydrochloric acid, hydrobromic acid, hydriodic acid, sulfonic acids including such agents as naphthalenesulfonic, methanesulfonic and toluenesulfonic acids, sulfuric acid, nitric acid, phosphoric acid, tartaric acid, pyrosulfuric acid, metaphosphoric acid, succinic acid, formic acid, phthalic acid, lactic acid and the like, most preferable with hydrochloric acid, citric acid, benzoic acid, maleic acid, acetic acid and propionic acid. It is usually preferred to administer a compound of this invention in the form of an acid addition salt, as it is customary in the administration of pharmaceuticals bearing a basic group such as the piperidino ring.
When it is desired to prepare a compound of formula 1 of this invention with one or more ether groups, the ether is prepared by placing the R10 moiety on one or more of the hydroxy groups in a manner commonly used for the preparation of ethers. For example, the R10 group may be added by reaction with appropriate diazo compound, such as diazomethane, phenyldiazomethane or trimethylsilyldiazomethane (see Hashimoto et al., Tet. Let., 4619-22 (1980).) Such reactions are effectively carried out in solvents including esters such as ethyl acetate, halogenated solvents including dichloromethane and chloroform, and ethers including diethyl ether and tetrahydrofuran. Methanol or boron trifluoride is used as a catalyst, and the process is usually carried out at low temperatures from about xe2x88x9245xc2x0 C. to about 0xc2x0 C.
Alternatively, alkylations may be carried out using R10X, where Xxe2x95x90 Br I, mesylate (xe2x88x92OMs), and a base, sodium hydride or potassium carbonate, for example, in a dipolar aprotic solvent such as dimethylformamide at ambient or elevated temperatures.
It is preferable to prepare monoethers by using an ultimate starting compound in the mono-ether form, and using the ether group as a protecting group through the synthesis, protecting other hydroxy groups with an acyl or sulfonyl group.
When a compound is desired with one or more ester groups, it may often be most convenient to prepare the compound using a protecting group other than the desired ester group, hydrolyze off the protecting group and re-acylate one or both of the hydroxy groups at the end of the synthesis. Such acylations are carried out as described below in the discussion of 
groups as protecting groups. A particularly preferred condition for final acylalions is to use tetrahydrofuran as the solvent and potassium carbonate as the acid scavenger for acylating agents such as acetic anhydride, benzoyl chloride, ethyl chloroformate and the like.
The compounds of this invention, as discussed above, are very often administered in the form of acid addition salts. The salts are conveniently formed, as is usual in organic chemistry, by reacting the compound of this invention with a suitable acid, such as have been described above. The salts are quickly formed in high yields at moderate temperatures, and often are prepared by merely isolating the compound from a suitable acidic wash as the final step of the synthesis. The salt-forming acid is dissolved in an appropriate organic solvent, or aqueous organic solvent, such as an alkanol, ketone or ester. On the other hand, if the compound of this invention is desired in the free base form, it is isolated from a basic final wash step, according to the usual practice. A preferred technique for preparing hydrochlorides is to dissolve the free base in a suitable solvent and dry the solution thoroughly, as over molecular sieves, before bubbling hydrogen chloride gas through it.
The dose of a compound of this invention to be administered to a human is rather widely variable and subject to the judgement of the attending physician. It should be noted that it may be necessary to adjust the dose of a compound when it is administered in the form of a salt, such as a laurate, the salt forming moiety of which has an appreciable molecular weight. The general range of effective administration rates of the compounds is from about 0.05 mg/kg/day to about 50 mg/kg/day. A preferred rate range is from about 1 mg/kg/day to 10 mg/kg/day. Of course, it is often practical to administer the daily dose of compound in portions, at various hours of the day. However, in any given case, the amount of compound administered will depend on such factors as the solubility of the active component, the formulation used and the route of administration.
The route of administration of the compounds of this invention is not critical. The compounds are known to be absorbed from the alimentary tract, and so it is usually preferred to administer a compound orally for reasons of convenience. However, the compounds may equally effectively be administered percutaneously, or as suppositories for absorption by the rectum, if desired in a given instance.
The compounds of this invention are usually administered as pharmaceutical compositions which are important and novel embodiments of the invention because of the presence of the compounds. All of the usual types of compositions may be used, including tablets, chewable tablets, capsules, solutions, parenteral solutions, troches, suppositories and suspensions. Compositions are formulated to contain a daily dose, or a convenient fraction of daily dose, in a dosage unit, which may be a single tablet or capsule or convenient volume of a liquid.
Any of the compounds may be readily formulated as tablets, capsules and the like; it is preferable to prepare solutions from water-soluble salts, such as the hydrochloride salt.
In general, all of the compositions are prepared according to methods usual in pharmaceutical chemistry.
Capsules are prepared by mixing the compound with a suitable diluent and filling the proper amount of the mixture in capsules. The usual diluents include inert powdered substances such as starch of many different kinds, powdered cellulose, especially crystalline and microcrystalline cellulose, sugars such as fructose, mannitol and sucrose, grain flours and similar edible powders.
Tablets are prepared by direct compression, by wet granulation, or by dry granulation. Their formulations usually incorporate diluents, binders, lubricants and disintegrators as well as the compound. Typical diluents include, for example, various types of starch, lactose, mannitol, kaolin, calcium phosphate or sulfate, inorganic salts such as sodium chloride and powdered sugar. Powdered cellulose derivatives are also useful. Typical tablet binders are substances such as starch, gelatin and sugars such as lactose, fructose, glucose and the like. Natural and synthetic gums are also convenient, including acacia, alginates, methylcellulose, polyvinylpyrrolidine and the like. Polyethylene glycol, ethylcellulose and waxes can also serve as binders.
A lubricant is necessary in a tablet formulation to prevent the tablet and punches from sticking in the die. The lubricant is chosen from such slippery solids as talc, magnesium and calcium stearate, stearic acid and hydrogenated vegetable oils.
Tablet disintegrators are substances which swell when wetted to break up the tablet and release the compound. They include starches, clays, celluloses, algins and gums. More particularly, corn and potato starches, methylcellulose, agar, bentonite, wood cellulose, powdered natural sponge, cation-exchange resins, alginic acid, guar gum, citrus pulp and carboxymethylcellulose, for example, may be used as well as sodium lauryl sulfate.
Tablets are often coated with sugar as a flavor and sealant, or with film-forming protecting agents to modify the dissolution properties of the tablet. The compounds may also be formulated as chewable tablets, by using large amounts of pleasant-tasting substances such as mannitol in the formulation, as is now well-established in the art.
When it is desired to administer a compound as a suppository, the typical bases may be used. Cocoa butter is a traditional suppository base, which may be modified by addition of waxes to raise its melting point slightly. Water-miscible suppository bases comprising, particularly, polyethylene glycols of various molecular weights are in wide use.
The effect of the compounds may be delayed or prolonged by proper formulation. For example, a slowly soluble pellet of the compound may be prepared and incorporated in a tablet or capsule. The technique may be improved by making pellets of several different dissolution rates and filling capsules with a mixture of the pellets. Tablets or capsules may be coated with a film which resists dissolution for a predictable period of time. Even the parenteral preparations may be made long-acting, by dissolving or suspending the compound in oily or emulsified vehicles which allow it to disperse only slowly in the serum.
The following typical formulae are provided further to assist the formulations chemist.
General Methods for the Preparation of Compounds of Formula 1
The methods described in Part 1 illustrate the synthesis of the estrogen agonists of Formula I.
Part 1
Scheme 1 illustrates a general route to compounds I. Methyl 4-hydroxybenzoate is alkylated with 1-bromo-2-chloroethane using sodium ethoxide in refluxing ethanol to yield 1-1. Base hydrolysis and treatment with thionyl chloride produced the acid chloride 1-3 which was used crude. The benzothiophene 1-4, prepared as in Journal of Medicinal Chemistry 27, 1984, 1057, was acylated with 1-3 using triflic acid in refluxing methylene chloride to afford the chloride 1-5. Treatment with sodium iodide in refluxing acetone yields the iodide 1-6. Alkylation of various amines with 1-6 is usually carried out either with potassium or cesium carbonate in DMF. Aromatic heterocycles are N-alkylated by 1-6 by first converting them to sodium salts with sodium hydride in DMF. Basic hydrolysis of 1-7 with potassium hydroxide or potassium carbonate afforded compounds of Formula I. Table 1 lists some of the compounds made by this method. Other protecting groups for the phenols like the methyl ether, which can be deprotected with ethanethiol and aluminum trichloride or by boron tribromide, may also be used. The amines were either commercially available or prepared by known routes. Compound 1-8 is prepared by oxidizing the iodide 1-6 with m-CPBA in methylene chloride followed by basic hydrolysis.
Part 2
The methods described in Part 2 illustrate the preparation of compounds of Formula II. One general approach to some of these compounds is to attach the groups represented by Z to C-3 of a suitably protected benzothiophene 2-1 by Lewis acid catalyzed acylation (Scheme 2). The ketones thus produced can be reduced to the alcohols or methylene analogs 2-3, 2-4 respectively by lithium aluminum hydride or lithium aluminum hydride-aluminum trichloride for example. Deprotection of 2-2, 2-3, 2-4 affords compounds of general formula II.
Alternately, as illustrated in Scheme 3, a suitably protected benzothiophene 2-1 derivative can be brominated, either with bromine buffered with sodium acetate or N-bromosuccinimide in a chlorinated solvent, to yield 3-1 which can be lithiated by tert-butyllithium in THF at xe2x88x9278xc2x0 C. and quenched with an aldehyde to generate 3-2 which can be oxidized with activated manganese dioxide, for example, and deprotected to afford compounds of Formula II. Compound 3-2 can also be reduced to the methylene compound with sodium borohydride and trifluoroacetic acid, for example.
Scheme 4 illustrates a route to compounds 4-3. Acylation of 2-1 with various chloro or bromo substituted nitrogen containing heterocyclic acid chlorides under aluminum trichloride or other Lewis acids catalysis in methylene chloride or 1,2-dichloroethane yields 4-1. By heating 4-1 with various amines, potassium iodide and sodium bicarbonate or sodium alkoxides in polar solvent, like DMF, 4-2 is prepared. Or 4-1 can be reacted with various alcohols under phase transfer conditions, for example, toluene, sodium hydroxide and 18-crown-6, to afford 4-2. Deprotection of 4-2 to yield 4-3 can be achieved by methods known to those skilled in the art.
Acylation of 2-1 with 4-acetoxybenzoyl chloride is achieved with aluminum trichloride in methylene chloride to yield 5a-1 after base hydrolysis of the acetate. (Scheme 5a) A preferred method to synthesize compound 5a-1 is to acylate 2-1 with p-anisoyl chloride then, to selectively demethylate the methoxy group para to the carbonyl group with lithium ethanethiolate in a polar aprotic solvent like dimethyl formamide at 50 through 80xc2x0 C. Phenol 5a-1 can be alkylated either with bases like potassium carbonate in acetone or dimethyl formamide and various alkyl halides or mesylates or with various alcohols under Mitsonobu conditions (triphenylphosphine and diethydiazodicarboxylate in tetrahydrofuran to yield compounds 5a-2 and, after deprotection 5a-3. Scheme 5b illustrates a general route to compounds of Formula III. The required starting alcohols 5b-1 are commercially available as the free amines or they can be prepared by reduction of the corresponding acid or esters, for example. They may also be available from the amide 5c-1 by organometallic addition followed by reduction and deprotection to 5b-1 (See Scheme 5C). Mitsonobu coupling to 5a-1 affords 5b-2 which can be debenzylated with hydrogen over Pd/C in alcoholic solvent containing acetic acid to 5b-3. Reductive amination with various aldehydes or ketones leads to 5b-4 then to compounds of Formula III after deprotection.
Iodide 6a-1, prepared by aluminum trichloride acylation of 2-1 with 4-iodobenzoyl chloride, is a valuable intermediate. (Scheme 6a) Heck reaction of 6a-1 and various olefins affords the trans olefins 6a-2 which can be deprotected to provide 6a-3. A typical set of conditions for the Heck reaction is palladium acetate, tri-ortho-tolylphosphine, tributylamine in N-methypyrrolidinone at temperatures varying from room temperature to 120xc2x0 C. Hydrogenation of 6a-2 over palladium on carbon affords the saturated analogs 6a-4 which can be deprotected to yield 6a-5. Propargyl alcohol and other acetylenic alcohols can be coupled to 6a-1 with cuprous iodide and bistriphenylphosphine palladiumdichloride in triethylamine at room temperature to give 6a-6, mesylation with methanesulfonyl chloride and a tertiary amine base provides 6a-7. Alkylation of various amines afford 6a8. Hydrogenation affords the cis olefins 6a-9, trans-olefins 6a-10 and the saturated compound 6a-5, after deprotection. Vinylation of 6a-1, Scheme 6b, can be achieved by treatment with vinyltributyltin and bistriphenylphosphine palladiumdichloride in refluxing dioxane or dimethoxyethane to afford 6b-1. Oxidative cleavage to the aldehyde 6b-2 can be achieved with catalytic osmium tetroxide and sodium periodate in tert-butanol and water at room temperature. Reduction with mild reducing agents like sodium borohydride yields the alcohol 6b-3 that can be alkylated by various alkyl halides with bases like sodium hydride in tetrahydrofuran or dimethylformamide to give 6b-4. The reactions illustrated in Scheme 6a and 6b can also be used to prepare the corresponding heterocyclic analogs by starting with 6c-1. Compound 6c-1 can be made by acylating 2-1 with heterocyclic acid chlorides substituted with bromides, iodides or trifluoromethanesulfonates.
Compound 3-1 can be metallated with tert-butyllithium in an ethereal solvent at low temperatures, usually xe2x88x9278xc2x0 C., and the resulting 3-lithiobenzothiophene can be quenched with either carbon dioxide or dimethylformamide to yield the acid, 7-1, or the aldehyde, 7-2, respectively after acid workup. The acid 7-1 can be converted to the Weinreb amide, 7-3, by reaction with N,O-dimethylhydroxylamine and a standard carbodiimide coupling reagent in a chlorinated solvent. The amide 7-3 can be coupled with various Grignard reagents or organolithiums, for example 7-4, to afford the ketones 7-5 after deprotection. The aldehyde 7-2 can be similarly coupled with organometallic reagents to yield 7-5 after oxidation and deprotection.
Part 3
3-Aminobenzenethiol is alkylated on the sulfur by xcex1-bromo4-methoxyacetophenone in ethanolic potassium hydroxide to yield 8a-1. (Scheme 8a) The amine is acetylated by acetic anhydride, 4-dimethylaminopyridine and pyridine in methylene chloride to afford 8a-2. Dehydrative closure of 8a-2 with polyphosphoric acid at 80xc2x0 C. affords the benzothiophene 8a-3 which was acylated on treatment with 8a-4 for example (prepared as in Journal of Medicinal Chemistry 1984, 27, 1057) and aluminum trichloride in methylene chloride to afford 8a-5 after demethylation in the same pot with ethanethiol and aluminum trichloride at room temperature. Hydrolysis of 8a-5 with 5N sodium hydroxide in refluxing ethanol affords the useful intermediate amine 8a-6, which can be formylated with formic acetic anhydride in THF to yield 8a-7 or sulfonylated with sulfonyl chlorides to afford the sulfonamides, like the methylsulfonamide 8a-8. Amine 8a6 can be reacted with other acyl chlorides to form various amides 8a-9 or isocyanates to form carbamates 8a-10 usually with a tertiary amine in methylene chloride.
Scheme 8b outlines the synthesis of 8b-4, a valuable intermediate. As in Scheme 9 using 4-methansulfonyloxy iodobenzene, 8b-1, can be prepared from 6-methoxybenzothiophene, 9-2. Demethylation using boron tribromide in methylene chloride affords 8b-3 which can be reacted with trifluoromethanesulfonic anhydride and 4-dimethylaminopyridine in methylene chloride to afford the triflate 8b-4. Palladium catalyzed carbonylation and methanol quench leads to the methyl ester 8b-5 which can be hydrolysed with aqueous base to the acid 8b-6 that can be reacted with various amines and dicyclohexylcarbodiimide to form amides 8b-7. Alternately palladium catalyzed carbonylation in the presence of tributyltin hydride yields the aldehyde 8b-8 which can reduced to the alcohol 8b-9 with mild reducing agents like sodium borohydride.
Electrophilic fluorination can be carried out on 2-1 by treating with N-fluorobenzenesulfonamide to yield the corresponding fluoride 8c-1. (Scheme 8c) Altematively lithiation at the C7 position of the benzothiophene occurs with butyllithium in THF, the resulting anion can be quenched with N-halosuccinimide to yield the corresponding bromide and iodide 8c-2, 8c-3 which are also useful intermediates for palladium catalyzed cross-coupling reactions in an ethereal solvent with various alkenyl, aryl or heteroaryl zinc or trialkyltin reagents, which can be prepared from the corresponding Grignards by treatment with zinc chloride or trialkyltin chloride, to prepare 8c-4. A common palladium catalyst is tetrakistriphenylphosphine palladium (0). Compounds 8c-1-4 can be acylated with an acid chloride to provide 8c-5.
Part 4
6-methoxybenzothiophene,9a-2, prepared in two steps from 3-methoxybenzenethiol and 2-bromo-1,1-diethoxyethane (Scheme 9a), is lithiated with n-butyllithium in THF at 0xc2x0 C. then treated with zinc chloride solution in THF to generate the organozinc reagent that is used immediately in the next step. Cross-coupling between this benzothiophene zinc reagent and alkenyl, aryl or heteroaryl bromides, iodides or triflates is achieved under catalysis by tetrakis (triphenylphosphine)palladium in THF at room temperature or reflux to afford 9a-3 where R is unsaturated. When R is saturated, Scheme 9a is modified slightly. Cross-coupling is carried out as above between the benzothipheneorganozinc and enol triflates (prepared from the corresponding ketones with lithium diisopropylamide then N-phenyltrifluoromethanesulfonimide at xe2x88x9278xc2x0 C. in THF) with anhydrous lithium chloride added to give, for example, 9a-5 which is hydrogenated over palladium on carbon to yield 9a-6 Both 9a-3 and 9a-5 can be acylated with an acid chloride, like 8a-4, under Lewis acid catalysis, aluminum trichloride or titanium tetrachloride for example, in methylene chloride or dichloroethane at room temperature or at reflux to afford 9a-4 and 9a-7 after standard demethylation with ethanethiol and aluminum trichloride.
Altemately, compound 9a-4 and 9a-7 can be prepared as in Scheme 3, by brominating 9a-3 with bromine, then metal halogen exchange followed by quench with an appropriate aldehyde, oxidation and deprotection.
Alternatively, as in Scheme 9b, 6-methoxybenzothiophene is brominated by N-bromosuccinimide in chloroform at reflux to provide 2-bromo-6-methoxybenzothiophene 9b-1 which can be acylated with acid chlorides like 8a-4 under Lewis acid or triflic acid catalysis in methylene chloride to provide 9b-2. Heck couplings with olefins as described above can provide 2-alkenyl compounds 9b-3 or alkyl 9b-4 after hydrogenation. Alternatively cross-coupling reactions between bromide 9b-2 and aryl or heteroaryl zinc or magnesium reagents catalyzed by palladium (0) catalysts like tetrakis(triphenylphosphine)palladium can provide 2-substituted benzothiophene derivatives 9b-5. Demethylation of 9b-3-5 afford compounds 9b-6.
Scheme 10a describes the synthesis of the indoles 10a-4. A suitably protected amino phenol is heated to around 170xc2x0 C. with a xcex1-bromoketone to generate the 2-substituted indole 10-1. This may be N-alkylated by deprotonation with a base like sodium amide in tetrahydrofuran and alkylated with various alkyl halides to yield 10a-2. Both 10a-1 and 10-1 can be acylated with acid chlorides to afford the 3-keto indoles 10a-3 which can be deprotected to the desired indoles 10a-4. 
